Bosch Stainless Steel Blender Rust Issue

I purchased a Bosch stainless steel blender with a glass pitcher. It hasn't even been a year, and I noticed rust at the blade's junction. I called Bosch customer service at 444 6333, explaining that their so-called stainless steel blender had rusted. They promised to send a service technician.

The next day, the technician arrived and initially tried to wipe the rust, claiming it wasn’t rust. He then demanded a service fee. After insisting and contacting customer service again, the technician wiped the area with alcohol and admitted it was rust but said rust wasn’t covered under warranty. I bought this product because it was advertised as stainless steel, so how can it rust?

Moreover, if rust isn’t covered under warranty, why wasn’t I informed from the beginning? When I called customer service, I specifically mentioned it was rust, and no one told me rust wasn’t covered. Is this a ploy to charge for service fees? Trusting Bosch, a reputable company, I expected a rust-free product. Upon escalating, I was transferred to the headquarters, where they claimed it was user error. I only use this blender to make smoothies with bananas and milk, and despite it being dishwasher safe, I hand-wash it to be careful. How could I cause it to rust by making smoothies and washing it carefully?

When I mentioned this to Ms. B****, she stated that stainless steel doesn’t rust unless it’s user error. I questioned how they could be so sure without testing, to which she replied that they conduct R&D tests on their products. I shared an experience with a waterproof watch that leaked, which was replaced after inspection. They dismissed this comparison, saying watches and blenders are different. I even bought another of the same blender as a gift, which also rusted. Are they suggesting the recipient used it incorrectly as well?

Bosch has lost my trust completely. I will never purchase another product from them. They sell products as stainless steel that rust, and their only response is to blame the customer without proper inspection.